The laminated coil component disclosed in Japanese Unexamined Patent Application Publication No. 2006-66764 is known as an existing example of a laminated coil component. This laminated coil component is configured by laminating a plurality of magnetic layers and a plurality of coil conductors in a lamination direction. In a cross-section taken along a width direction of the coil conductors, a lower surface of each coil conductor makes contact with a magnetic layer, and a hollow cavity portion is formed between a magnetic layer, and an upper surface and both width direction side surfaces of the coil conductor.
The presence of this hollow cavity portion makes it possible to suppress stress on the magnetic layers caused by changes in the temperature of the coil conductors, which are caused by a difference in the thermal expansion coefficients of the coil conductors and the magnetic layers. As a result, deterioration of inductance and impedance characteristics caused by internal stress can be eliminated.
Incidentally, diligent examinations of the above-described laminated coil component indicated that small-loop magnetic fluxes are produced in the periphery of the individual coil conductors. The small-loop magnetic fluxes overlap with large-loop magnetic fluxes produced by multiple coil conductors and passing through the centers of the coil conductors, which was found to influence the inductance.